1. Field of Invention
The present invention relates to a microprocessor-based remote control unit which operates on a dial-up telephone network. More particularly, the present invention pertains to a remote control unit which provides verbal communication to a remote site regarding status of certain monitored conditions and parameters, with capability for corrective action being initiated by remote control.
2. Prior Art
The typical configuration of a broadcast operation for radio or television includes a studio here programming is conducted and certain control circuitry operated and a transmitter which is usually remote from the studio and positioned at a preferable location for good transmission of the radio or television signal. By establishing a remote control link from the studio to the transmitter, broadcast expenses may be reduced by eliminating on-site personnel from the transmitter site. Existing broadcast transmitter remote control systems have previously consisted of a transmitter unit and a studio unit. These have been located at their respective studio and transmitter locations and have been interconnected with a dedicated circuit such as a telephone line having continuous and exclusive application to the interconnected remote control units. Sensors and other testing devices are connected at inputs of the transmitter remote control unit and provide real time measurement of operational parameters such as plate voltage, operating temperatures, current levels, power consumption, reflected power measurements, standby power, filament status, status of auxiliary operating systems, tower lights, etc. In addition, environmental conditions are monitored such as unlawful intrusion, open doors or windows, temperature, flooding or excessive water conditions, structural integrity of building and pertinent structures, and other environmental matters of interest.
The use of a dedicated telephone line constitutes a substantial expense, particularly in view of optional methods of utilizing existing telephone lines for periodic intermittant monitoring or transmission of operational parameters at the transmitter location. For example, it is well known that an existing telephone line provides an appropriate interconnective circuit from a monitoring device located at a particular facility and a remote telephone receiver which can be utilized to access data detected and/or stored in the monitoring device. The following U.S. patents illustrate various applications of monitoring systems which interconnect via conventional telephone lines:
U.S. Pat. No. 4,438,295 Hales PA1 U.S. Pat. No. 4,353,502 Myers PA1 U.S. Pat. No. 4,332,980 Reynolds, et al. PA1 U.S. Pat. No. 4,493,948 Sues, et al. PA1 U.S. Pat. No. 4,442,320 James, et al. PA1 U.S. Pat. No. 4,493,947 Loveless
The first five patents disclose remote systems for activating heating or cooling of a building, for monitoring its temperature or for otherwise providing remote detection of breach of security, burglary, fire or other emergency conditions. Typically, the occurrence of such a condition automatically activates a telephone dialing sequence which dials a pre-program med and number and transmits a code or alarm signal. The Hales patent permits the remote listener to call the building location over a remote phone, allowing the phone to ring a predetermined number of times to thereupon automatically activate a furnace or air conditioner system. The Loveless patent discloses a monitoring systems which also includes a device identifier transmission and use of a microphone to detect sounds at the environment of the monitoring device and to transmit those sounds to the telephone user.
Although such basic devices are useful in monitoring existence of emergency conditions such as burglary, fire and environmental conditions such as temperature, the complexity of monitoring and regulating a remote transmitter station for radio or television broadcasting poses additional complexities which have discouraged efforts to use non-dedicated telephone lines and oversimplified systems. It is apparent that an unmanned transmitter station broadcasting radio or television signals over great distances must be subject to immediate control, problem detection and access for immediate correction to prevent a serious condition of interference, as well as loss of transmission services with resultant economic effects. For these reasons, the Federal Communications Commission has regulated remote control of transmitter stations for many years. Improved equipment and practice has recently permitted easing of some aspects of remote control. For example, the point of remote control no longer needs to be the studio or at some other location which is registered and on file with the Commission. It is now permissible to activate remote control from any location. Such deregulation develops even greater incentive for development of a remote control system capable of operating over nondedicated telephone interconnecting circuits. Specifically, new regulations allow accessing the remote control unit at the transmitter location via any telephone connection, including locations unassociated with the broadcasting studio. Nevertheless, such remote control operation still mandates appropriate security and application of sound engineering practice which protects the public welfare, as well as providing competent operation of the broadcast system.
What is needed, is a remote control system which retains critical capabilities for recording data and out-of-tolerance conditions, alarm reporting, accurate metering of operational parameters, and fully secured access control, as well as providing such features over an open, public switched telephone network. Even more significant is the ability to meet such stringent remote operation requirements within a "user-friendly" system which can be operated by nontechnical personnel in accordance with simple procedures.